JP2018160314A - Method of manufacturing display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress peeling failure from a substrate in manufacturing of a flexible display.SOLUTION: A method of manufacturing a display device includes the steps of: forming a through groove penetrating through a base material in a thickness direction by surrounding a display region on a laminate including a substrate and the base material having the display region formed on the substrate; and peeling the substrate from the base material by irradiating the laminate with laser beams in this order. When the laser beams are irradiated, in a region overlapping with the end of the laminate and not overlapping with the display region, a light shielding part for shielding the laser beams is formed and the through groove is arranged in a position closer to the display region side than the light shielding part.SELECTED DRAWING: Figure 5B

Description

  The present invention relates to a method for manufacturing a display device.

  In display devices having a display region such as an organic electroluminescence (EL) display device and a liquid crystal display device, in recent years, development of a flexible display capable of bending a display panel using a flexible substrate has been advanced. Yes.

  For example, as disclosed in Patent Documents 1 and 2 below, the flexible base material is supported by a substrate (for example, a glass substrate) in the manufacturing process of the display panel from the viewpoint of handling properties and the like. Is peeled from the substrate at any suitable timing.

JP 2011-187446 A JP 2014-120664 A

  However, peeling failure from the substrate may occur, which may cause display failure of the display panel, for example.

  In view of the above, an object of the present invention is to provide a method for manufacturing a display device in which poor peeling from a substrate is suppressed.

  The display device manufacturing method according to the present invention includes a through-groove that surrounds the display region in a laminate including a substrate and a substrate having a display region formed on the substrate, and penetrates the substrate in the thickness direction. , Irradiating the laminated body with laser light and peeling the substrate from the base material in this order, and upon irradiation with the laser light, overlapping the end of the laminated body and the A light-shielding portion that shields the laser light is formed in a region that does not overlap the display region, and the through groove is disposed on the display region side of the light-shielding portion.

It is a schematic diagram which shows the structure of the outline of the organic electroluminescence display which concerns on one Embodiment of this invention. FIG. 2 is a schematic plan view illustrating an example of a display panel of the organic EL display device illustrated in FIG. 1. It is a figure which shows an example of the III-III cross section of FIG. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus in one embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus in one embodiment of this invention. It is a figure for demonstrating the manufacturing method of the organic electroluminescent display apparatus in one embodiment of this invention. It is the top view which looked at the display panel at the time of laser beam irradiation in one embodiment of the present invention from the substrate side. It is a figure which shows an example of the II cross section of FIG. 5A. It is a figure which shows an example of the II-II cross section of FIG. 5A.

  Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention are naturally included in the scope of the present invention. In addition, the drawings may be schematically evaluated with respect to the width, thickness, shape, and the like of each part as compared with actual embodiments for clarity of explanation, but are merely examples, and are interpreted as the interpretation of the present invention. It is not intended to limit. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings may be denoted by the same reference numerals and detailed description thereof may be omitted as appropriate.

  FIG. 1 is a schematic diagram showing a schematic configuration of a display device according to an embodiment of the present invention, using an organic EL display device as an example. The organic EL display device 2 includes a pixel array unit 4 that displays an image and a drive unit that drives the pixel array unit 4. The organic EL display device 2 is a flexible display using a resin film as a base material, and a laminated structure such as a thin film transistor (TFT) or an organic light emitting diode (OLED) is formed on the base material made of the resin film. The The schematic diagram shown in FIG. 1 is an example, and the present embodiment is not limited to this.

  In the pixel array unit 4, OLEDs 6 and pixel circuits 8 are arranged in a matrix corresponding to the pixels. The pixel circuit 8 includes a plurality of TFTs 10 and 12 and a capacitor 14.

  The drive unit includes a scanning line drive circuit 20, a video line drive circuit 22, a drive power supply circuit 24, and a control device 26, and drives the pixel circuit 8 to control light emission of the OLED 6.

  The scanning line driving circuit 20 is connected to a scanning signal line 28 provided for each horizontal arrangement (pixel row) of pixels. The scanning line driving circuit 20 sequentially selects the scanning signal lines 28 according to the timing signal input from the control device 26, and applies a voltage for turning on the lighting TFT 10 to the selected scanning signal lines 28.

  The video line driving circuit 22 is connected to a video signal line 30 provided for each vertical arrangement (pixel column) of pixels. The video line driving circuit 22 receives a video signal from the control device 26, and in accordance with the selection of the scanning signal line 28 by the scanning line driving circuit 20, a voltage corresponding to the video signal of the selected pixel row is applied to each video signal line. Output to 30. The voltage is written into the capacitor 14 via the lighting TFT 10 in the selected pixel row. The driving TFT 12 supplies a current corresponding to the written voltage to the OLED 6, whereby the OLED 6 of the pixel corresponding to the selected scanning signal line 28 emits light.

  The drive power supply circuit 24 is connected to a drive power supply line 32 provided for each pixel column, and supplies a current to the OLED 6 through the drive power supply line 32 and the drive TFT 12 of the selected pixel row.

  Here, the lower electrode of the OLED 6 is connected to the driving TFT 12. On the other hand, the upper electrode of each OLED 6 is configured by an electrode common to the OLED 6 of all pixels. When the lower electrode is configured as an anode (anode), a high potential is input, and the upper electrode is a cathode (cathode) and a low potential is input. When the lower electrode is configured as a cathode (cathode), a low potential is input, and the upper electrode is an anode (anode) and a high potential is input.

  FIG. 2 is a schematic plan view showing an example of the display panel of the organic EL display device shown in FIG. The pixel array unit 4 shown in FIG. 1 is provided in the display area 42 of the display panel 40, and the OLEDs 6 are arranged in the pixel array unit 4 as described above. As described above, the upper electrode constituting the OLED 6 is formed in common for each pixel and covers the entire display region 42.

  A component mounting area 46 is provided on one side of the rectangular display panel 40, and wirings connected to the display area 42 are arranged. In the component mounting area 46, a driver IC 48 constituting a driving unit is mounted, or a flexible printed circuit board (FPC) 50 is connected. The FPC 50 is connected to the control device 26 and other circuits 20, 22, 24, etc., and an IC is mounted thereon.

  FIG. 3 is a diagram illustrating an example of a III-III cross section of FIG. 2. In the display panel 40, a circuit layer 74 formed with TFTs 72 and the like, an OLED 6 and a sealing layer 106 that seals the OLED 6 are laminated on a base material 70 made of a resin film (or resin film). It has a structure. As resin which comprises the base material 70, a polyimide-type resin is used, for example. The base material 70 may be formed by coating a resin film containing a resin material such as polyimide. The base material 70 has flexibility. A protective film 114 is laminated on the sealing layer 106. A sheet-like or film-like protective film 114 may be bonded to the sealing layer 106 via an adhesive layer. In the present embodiment, the pixel array unit 4 is a top emission type, and light generated by the OLED 6 is emitted to the side opposite to the base material 70 side (upward in FIG. 3). When the colorization method in the organic EL display device 2 is a color filter method, for example, a color filter is disposed between the sealing layer 106 and the protective film 114 or on the counter substrate side (not shown). For example, red (R), green (G), and blue (B) light is produced by passing white light generated by the OLED 6 through the color filter.

  In the circuit layer 74 of the display area 42, the above-described pixel circuit 8, the scanning signal line 28, the video signal line 30, the drive power supply line 32, and the like are formed. At least a part of the drive unit can be formed as a circuit layer 74 on the substrate 70 in a region adjacent to the display region 42. As described above, the driver IC 48 and the FPC 50 constituting the driving unit can be connected to the wiring 116 of the circuit layer 74 in the component mounting region 46.

As shown in FIG. 3, a base layer 80 made of an inorganic insulating material is disposed on the base material 70. As the inorganic insulating material, for example, silicon nitride (SiN _y ), silicon oxide (SiO _x ), and a composite thereof are used.

  In the display region 42, a semiconductor region 82 serving as a channel portion and a source / drain portion of the top gate TFT 72 is formed on the base material 70 through the base layer 80. The semiconductor region 82 is formed of, for example, polysilicon (p-Si). The semiconductor region 82 is formed by, for example, providing a semiconductor layer (p-Si film) on the base material 70, patterning the semiconductor layer, and selectively leaving a portion used in the circuit layer 74.

  A gate electrode 86 is disposed on the channel portion of the TFT 72 via a gate insulating film 84. The gate insulating film 84 is typically formed of TEOS. The gate electrode 86 is formed by patterning a metal film formed by sputtering or the like, for example. An interlayer insulating layer 88 is disposed on the gate electrode 86 so as to cover the gate electrode 86. The interlayer insulating layer 88 is formed of, for example, the above inorganic insulating material. Impurities are introduced into the semiconductor region 82 (p-Si) serving as the source / drain portion of the TFT 72 by ion implantation, and further, a source electrode 90a and a drain electrode 90b electrically connected thereto are formed, and the TFT 72 is configured. Is done.

On the TFT 72, an interlayer insulating film 92 is disposed. A wiring 94 is disposed on the surface of the interlayer insulating film 92. For example, the wiring 94 is formed by patterning a metal film formed by sputtering or the like. The metal film forming the wiring 94 and the metal film used for forming the gate electrode 86, the source electrode 90a, and the drain electrode 90b include, for example, the wiring 116 and the scanning signal line 28, the video signal line 30, and the like shown in FIG. The drive power supply line 32 can be formed with a multilayer wiring structure. A planarizing film 96 and a passivation film 98 are formed thereon, and the OLED 6 is formed on the passivation film 98 in the display region 42. The planarizing film 96 is made of, for example, a resin material. The passivation film 98 is formed of an inorganic insulating material such as SiN _y , for example.

  The OLED 6 includes a lower electrode 100, an organic material layer 102, and an upper electrode 104. Specifically, the organic material layer 102 includes a hole transport layer, a light emitting layer, an electron transport layer, and the like. The OLED 6 is typically formed by laminating the lower electrode 100, the organic material layer 102, and the upper electrode 104 in this order from the base material 70 side. In the present embodiment, the lower electrode 100 is the anode (anode) of the OLED 6 and the upper electrode 104 is the cathode (cathode).

  If the TFT 72 shown in FIG. 3 is a driving TFT 12 having an n channel, the lower electrode 100 is connected to the source electrode 90 a of the TFT 72. Specifically, after the above-described planarization film 96 is formed, a contact hole 110 for connecting the lower electrode 100 to the TFT 72 is formed. For example, the surface of the planarization film 96 and the conductor portion formed in the contact hole 110. By patterning, the lower electrode 100 connected to the TFT 72 is formed for each pixel. The lower electrode is made of a transparent conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide), or a metal such as Ag or Al.

  On the above structure, ribs 112 for separating pixels are arranged. For example, after the formation of the lower electrode 100, ribs 112 are formed at the pixel boundaries, and the organic material layer 102 and the upper electrode 104 are laminated in an effective area of the pixel surrounded by the ribs 112 (an area where the lower electrode 100 is exposed). The The upper electrode 104 is made of, for example, a very thin alloy of Mg and Ag, or a transparent conductive material such as ITO or IZO.

A sealing layer 106 is disposed on the upper electrode 104 so as to cover the entire display region 42. The sealing layer 106 has a laminated structure including the first sealing film 161, the sealing planarization film 160, and the second sealing film 162 in this order. The first sealing film 161 and the second sealing film 162 are formed of an inorganic material (for example, an inorganic insulating material). Specifically, it is formed by forming a SiN _y film by chemical vapor deposition (CVD). The sealing planarization film 160 is formed using an organic material (for example, a resin material such as a curable resin composition). On the other hand, the sealing layer 106 is not disposed in the component mounting region 46.

  For example, the protective film 114 is laminated on the surface of the display region 42 in order to ensure the mechanical strength of the surface of the display panel 40. On the other hand, the protective film 114 is not provided in the component mounting area 46 for easy connection of IC and FPC.

  With reference to FIGS. 4A to 4C and FIGS. 5A to 5C, a method for manufacturing an organic EL display device in one embodiment of the present invention will be described. 4A to 4C, the structure of FIG. 3 is simplified to a three-layer structure of the base material 70, the upper structure layer 108, and the protective film 114. 5A to 5C, the upper structural layer 108 and the protective film 114 are omitted.

  First, as shown in FIG. 4A, a base material 70 having a display region 42, a frame region 44, and a component mounting region 46 is formed on a glass substrate 200 (also referred to as a support substrate or a substrate). Specifically, a desired thickness (for example, about 20 μm) is obtained by applying a forming material (for example, a resin composition) of the base material 70 on the glass substrate 200 and performing various treatments such as heating as necessary. ) Is formed. As a method for applying the forming material of the base material 70, a known method such as a spin coating method may be employed.

  Next, as shown in FIG. 4B, a circuit layer 74 including a TFT 72, a planarizing film 96, a passivation film 98, an OLED 6 and a sealing layer 106 are formed in this order on a base material 70 to form an upper structure. After forming the layer 108, a protective film 114 (for example, a resin film such as a PET film) is laminated on the upper structure layer 108 via an adhesive layer (not shown), and as shown in FIG. The glass substrate 200 is peeled off. Unlike the illustrated example, the glass substrate 200 may be peeled off before the protective film 114 is laminated on the upper structural layer 108.

  The glass substrate 200 is peeled off by, for example, irradiating laser light (for example, using an excimer laser) to reduce the adhesion between the glass substrate 200 and the base material 70. As the laser light, for example, a laser light having an appropriate wavelength is selected according to the material of the substrate and / or the base material.

  FIG. 5A is a plan view of the display panel viewed from the substrate side during laser light irradiation, FIG. 5B is a diagram showing an example of the II cross section of FIG. 5A, and FIG. 5C is the II-II cross section of FIG. It is a figure which shows an example. When irradiating the laser beam, as shown in FIG. 5B, a through groove 70 a penetrating the base material 70 in the thickness direction is formed in the base material 70 in advance. The through groove 70 a exposes a part of the main surface (first main surface) that contacts the base material 70 of the glass substrate 200. Further, the through groove 70a is formed in an annular shape so as to surround the display region 42 as indicated by a broken line in FIG. 5A. Specifically, a through groove 70 a is formed in the component mounting region 46 on one side of the rectangular base material 70 provided with the component mounting region 46. On three sides of the base material 70 where the component mounting area 46 is not provided, a through groove 70a is formed in the frame area 44 surrounding the display area. The frame region 44 is a region surrounding the display region 42 and is different from the display region 42 in that, for example, the TFT 72 and the OLED 6 are not included.

  In this embodiment, when the laser beam is irradiated, as shown in FIG. 5C, the FPC 50 is bonded to the base material 70 (specifically, the upper structure layer 108 formed on the base material 70). . The joint between the base material 70 and the FPC 50 is formed at a position spaced from the through groove 70a toward the display region 42 side. The FPC 50 is typically bonded to the base material 70 using an adhesive material (specifically, an adhesive material containing an anisotropic conductive material). Therefore, from the viewpoint of ensuring reliable peelability of the glass substrate 200, the through groove 70a is formed so that the adhesive layer 120 does not enter the through groove 70a. Specifically, when the FPC 50 is pressure-bonded, the through groove 70a is formed at a position where the adhesive layer 120 spreads and does not enter the through groove 70a. That is, as shown in FIG. 5C, the end portion (first end portion) of the base material 70 facing the through groove 70a and located on the display region 42 side with respect to the through groove 70a is in contact with the adhesive layer 120. With no area. In other words, between the end located on the side of the through groove 70a of the adhesive layer 120 and the end (or the side along the through groove 70a) facing the through groove 70a of the substrate 70, There is a predetermined gap, and the through groove 70a and the end of the adhesive layer 120 are separated from each other.

  The timing of forming the through groove 70a is not particularly limited as long as it is before peeling of the glass substrate 200 by laser light irradiation. For example, the through groove 70 a is formed after the sealing layer 106 is formed and before or after the protective film 114 is stacked. The through groove 70a is formed by, for example, removal by laser processing (cutting, ablation). The width of the through groove 70a is, for example, 30 μm to 40 μm.

  As shown in FIGS. 5A to 5C, when irradiating laser light, a mask 300 is disposed so as to cover the end portion of the glass substrate 200, and the laser light is shielded from the end portions of the glass substrate 200 and the base material 70. A light shielding portion is formed. The mask 300 may have a frame shape. The light shielding portion does not overlap the display area 42. Specifically, the through groove 70a is arranged on the inner side (display area 42 side) than the light-shielding portion to be formed. The mask 300 is formed of any appropriate material that can shield laser light. As a specific example, a metal plate (for example, an aluminum plate) is used as the mask 300. In the illustrated example, the mask 300 is disposed to form the light shielding portion. For example, vapor deposition or the like is performed on the end portion of the main surface on the laser beam irradiation side of the laminate including the glass substrate 200 and the base material 70. The light shielding portion may be formed by forming a metal layer. Before placing the base material 70 on the glass substrate 200, a frame-shaped metal layer is formed in advance on the entire outer periphery including the end of the main surface of the glass substrate 200 on the side irradiated with the laser light. Also good.

  Laser light irradiation is performed by scanning a laser light source in a predetermined direction. Specifically, the laser light source corresponding to the long side of the display area is scanned along the direction of the arrow shown in FIG. 5A. Preferably, as shown by the arrow in FIG. 5B, laser light is irradiated from the glass substrate 200 side.

  After the laser light irradiation, the glass substrate 200 is peeled from the base material 70 while leaving the end portion shielded by the mask 300 and inside the through groove 70a (with the through groove 70a as a peeling end). Thus, the laser light is shielded by the light shielding portion of the mask 300 at the end portions of the glass substrate 200 and the base material 70 (particularly, the end surface 200a of the glass substrate 200). The occurrence of foreign matter can be suppressed without hitting the part. As a result, excellent peelability of the glass substrate 200 can be realized. Specifically, when the laser light hits an end portion of a laminate including the glass substrate 200 and the base material 70, for example, foreign matter (particularly from the end surface 200a of the glass substrate 200) from the end portion of the glass substrate 200 and the base material 70 ( Cullet, etc.) are generated and scattered, and adhere to the surface of the laminate (particularly, the glass substrate 200). As described above, when the laser beam is irradiated in a state where foreign matter (particularly, a foreign matter of 15 μm or more) is attached, the laser light does not reach the interface between the glass substrate 200 and the base material 70 in the portion where the foreign matter exists. There is a possibility that the adhesion between the two is not sufficiently lowered. As a result, when the glass substrate 200 is peeled off, the substrate 200 and the base material 70 are not separated at the portion where the foreign matter exists, for example, a gap is generated between the layers of the organic material layer 102 with low adhesion. May cause display failure of the display panel. Such a malfunction is satisfactorily suppressed by forming a light-shielding portion at the end of the laminate (particularly the glass substrate 200).

  The present invention is not limited to the above embodiment, and various modifications can be made. For example, it can be replaced with a configuration that is substantially the same as the configuration shown in the above embodiment, a configuration that exhibits the same operational effects, or a configuration that can achieve the same purpose. For example, the form which peels a board | substrate from a base material before individualization may be employ | adopted instead of peeling a board | substrate after dividing | segmenting into each panel (piece | piece) like the said embodiment. Specifically, for a laminate including a substrate and a base material having a display area corresponding to a plurality of panels, a through groove is formed in the base material so as to surround the plurality of display areas, and then surrounded by the through groove. A form in which the substrate is peeled off by irradiating the region with laser light may be employed.

  2 organic EL display device, 4 pixel array unit, 6 OLED, 8 pixel circuit, 10 lighting TFT, 12 driving TFT, 14 capacitor, 20 scanning line driving circuit, 22 video line driving circuit, 24 driving power supply circuit, 26 control device, 28 scanning signal lines, 30 video signal lines, 32 drive power supply lines, 40 display panel, 42 display area, 44 frame area, 46 component mounting area, 48 driver IC, 50 FPC, 70 base material, 70a through groove, 72 TFT, 74 circuit layer, 80 underlayer, 82 semiconductor region, 84 gate insulating film, 86 gate electrode, 88 interlayer insulating layer, 90a source electrode, 90b drain electrode, 92 interlayer insulating film, 94 wiring, 96 planarization film, 98 passivation film , 100 Lower electrode, 102 Organic material layer, 104 Upper electrode, 106 Sealing layer, 1 8 upper structural layer, 110 a contact hole, 112 rib, 114 protective film, 116 wiring, 200 a glass substrate, 300 a mask.

Claims (17)

Forming a through groove that surrounds the display region and penetrates the base material in a thickness direction in a laminate including a substrate and a base material having a display region formed on the substrate;
Irradiating the laminate with a laser beam and peeling the substrate from the base material in this order,
Upon irradiation with the laser light, a light-shielding portion that shields the laser light is formed in a region that overlaps an end portion of the stacked body and does not overlap the display region, and the penetrating portion is closer to the display region than the light-shielding portion. Place the groove,
Manufacturing method of display device.   The method for manufacturing a display device according to claim 1, wherein a mask is disposed so as to cover the end portion of the stacked body to form the light shielding portion.   The method for manufacturing a display device according to claim 1, wherein the laser beam is irradiated from the substrate side of the laminate. The substrate has a main surface irradiated with the laser beam,
The manufacturing method of the display device according to claim 1, wherein the light shielding portion is formed in a frame shape on the entire outer periphery of the main surface including an end portion of the main surface. The base has a joint for joining parts with an adhesive material;
5. The method for manufacturing a display device according to claim 1, wherein the through groove is formed at a position separated from the joint portion on a side opposite to the display region.   After forming the circuit layer, the organic material layer sandwiched between the lower electrode and the upper electrode, and the sealing layer covering the display area in this order on the opposite side of the substrate from the substrate, the through groove The manufacturing method of the display apparatus in any one of Claim 1 to 5 which forms.   The method for manufacturing a display device according to claim 1, wherein the substrate is a glass substrate.   The method for manufacturing a display device according to claim 1, wherein the base material includes polyimide and has flexibility.   The method for manufacturing a display device according to claim 1, wherein the light shielding portion is made of metal. A base material forming step of forming a base material containing a resin on the support substrate;
On the base material, a display region forming step of forming a display region including a plurality of pixels,
A through groove forming step of forming a through groove that penetrates the base material and exposes a part of the first main surface that contacts the base material of the support substrate, outside the display region of the base material;
A light shielding part arrangement step of arranging a light shielding part that overlaps an end of the second main surface and does not overlap the display area on a second main surface opposite to the first main surface of the support substrate;
A method for manufacturing a display device, comprising: a peeling step of irradiating the second main surface with laser light to peel the base material and the support substrate.   The method for manufacturing a display device according to claim 10, wherein the light shielding portion does not overlap the through groove. The light shielding portion shields the laser light,
The method for manufacturing a display device according to claim 10, wherein the laser light is not irradiated to the end portion of the second main surface. The base material has a first part located on the display area side with respect to the through groove, and a second part located on the side opposite to the display area with respect to the through groove,
The method for manufacturing a display device according to claim 10, wherein in the peeling step, the first portion and the support substrate are peeled off. The through groove includes a linear portion,
The first portion includes a first end facing the linear portion, and a first side included in the first end and along the linear portion,
The first end portion has a bonding step of bonding a flexible printed circuit board through an adhesive material,
The method for manufacturing a display device according to claim 10, wherein an end portion of the adhesive layer located on the linear portion side and the first side are separated from each other. The light-shielding part is frame-shaped,
The method for manufacturing a display device according to claim 10, wherein the through groove has an annular shape surrounding the display area.   The method for manufacturing a display device according to claim 10, wherein the light shielding part is a mask disposed on the second main surface.   The method for manufacturing a display device according to claim 10, wherein the light shielding portion is a metal layer formed on the second main surface.

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